The point is, each additional step adds uncertainty:

1. Musk is highly likely to be a Nazi because
2. he very likely bought Twitter in order to promote Nazis, which we know because
3. after the acquisition, it's very likely that his actions have been to promote Nazis, which we know because
4. after the acquisition, the accounts we know have been promoted are right and far-right

In reverse order:

1. What if there are other actions in support of left-wing views our analysis has missed? What if the motivation was a belief that left-wing views were generally not being suppressed as much as right-wing views? (An easy belief to acquire, because the far-right are more violent than the far-left, so more often fall foul of rules against promotion of violence)
2. What if these far-right groups are horrible, but not actually Nazis?
3. What if Musk bought Twitter for other reasons, even though the actual effect has been promoting far-right/Nazis?

Let me be very clear: it is abundantly obvious that Musk is a Nazi. I am not trying to convince you that he isn't. I'm not trying to convince you that there was no reason to think he was a horrible shitstain in 2023; there absolutely was. But you and others in this thread are conflating convincing evidence with incontrovertible evidence. That's just a failure of empathy; people are unconvinced by convincing evidence all the damn time.